But they'll probably hear you laugh watching "Memory: The Origins of Alien," an entertaining new documentary about Ridley Scott's "Alien," which made its premiere at Sundance Film Festival late Thursday night.

Kane (John Hurt, on table) comes to a horrific end as Ripley (Sigourney Weaver), Parker (Yaphet Kotto), Dallas (Tom Skerritt) and Ash (Ian Holm) try to help in the 1979 sci-fi thriller "Alien."(Photo: ROBERT PENN, 20TH CENTURY FOX)

Anyone who's seen "Alien" knows precisely what we're talking about: that grisly moment when Kane (John Hurt), splayed across a table on the spaceship Nostromo, convulses in pain as a small alien creature bursts from his chest. Splattered with their now-deceased colleague's blood, Ripley (Weaver) and the crew look on in terror, before the monster wriggles out of the room.

It's an indelible scene in movie history that was also quite humorous for the people behind it. Some of the more amusing tidbits we learned from the film:

An early interpretation of the "chestburster" alien drawn by screenwriter Dan O'Bannon.(Photo: THE O'BANNON ESTATE)

The original alien looked a lot like a penis.

"Memory" (which is still seeking distribution) explores the "chestburster" scene at length, starting with the look of the alien itself, which was heavily drawn from Francis Bacon's 1944 painting "Three Studies for Figures at the Base of a Crucifixion." Scott, screenwriter Dan O'Bannon and production designer H.R. Giger were also inspired by parasitic wasps, who are known to eat caterpillars from the inside out.

But early prototypes of the alien puppet weren't scary at all, resembling a plump, featherless chicken, a small dinosaur and – as one woman who worked on the movie points out – a penis with razor-sharp teeth.

The set reeked, thanks to cow innards.

Scott and Giger eventually settled on a cobra-like alien puppet, which took the film crew nearly four hours to rig up inside Hurt's shirt (during which time, he laid on the table drinking red wine and smoking cigarettes). They then stuffed his shirt with cow organs purchased from a local butcher shop, to give the appearance of Kane's guts spilling out. Cast member Veronica Cartwright (who played Lambert) laughingly remembers it smelling awful, making it difficult to stand near Hurt.

All that stage blood was super-slippery.

Once they were finally ready to shoot, it actually took a few tries for the alien to rip out of Hurt's shirt. (Hilarious outtakes of it getting stuck inside are included in "Memory," which drew the biggest chuckles from audience members at an early screening.) But the crew kept on pumping fake blood inside, so by the time the anticipated "chestburst" happened, the entire cast and room were covered in it. Cartwright remembers slipping and falling on the floor during filming but quickly recovered by the end of the scene.

We're so used to seeing "Game of Thrones" star Lena Headey, center, in a wig that we almost don't recognize her with her own hair. The same goes for her "Fighting With My Family" co-star Nick Frost, second from right, who was rocking a bushy beard at the Vulture Spot on Sunday. Daniel Boczarski/Getty Images

Rashid Johnson, director of "Native Son," posed with cast members Ashleigh Morghan, Nick Robinson and Sanaa Lathan at the premiere of the film on Sundance's opening night Thursday. Chris Pizzello/Invision/AP